1 research outputs found
Detection and study of a high magnitude seismic event from GPS data: Case study of the 2011 Tohoku-Oki earthquake
The advent of GPS provided a new way of measuring surface displacements due to earthquakes by deploying GPS
networks within active seismic areas. Japan is located in the confluence of several tectonic plates, hence its seismicity.
In order to surveille this activity, one of wider GPS network in the world was deployed, i.e., GEONET. By processing
data from 93 GEONET reference stations, we analyze the 2011 Tohoku-Oki earthquake using PPP strategy. We stu-
died the time series during the event setting up a threshold value at we consider the time series are being altered by
the earthquake. We also identified the time after the occurrence when the maximum displacements happen. With the
study of these two parameters, we aim to show their different behavior as the main shock propagates along the Japan
islands, with a focus on a better understanding of the earthquake and its propagation. To achieving this, a least square
adjustment method was used to relate epicentral distance to topocentric displacements and the time of detection to
epicentral distance. The results show an exponential behavior of the distance-displacement regression versus a linear
behavior of the distance-time regression. Besides, we use the former linear regression to calculate and approximation
of the velocity of the shock wave